Global Warming vs. Global Warning

Faculty of Basic Sciences and Humanities

Dr. RPCAU , SAMASTIPUR, PUSA, BIHAR

PRESENTED TO : Mr. A.A.DAUDI

PRESENTED BY : SIMPAL KUMAR SUMAN

B.Tech(Biotech.) Roll no. : BT/18/15

What is Global Warming? Definition- The increase in earth’s average surface temperature due to rising levels of greenhouse gases. (In a 2008 NASA article on usage, defined by Erik M. Conwey )Term global warming first use was in 1978 science articles by geochemist Wallace Brocker of Coulumbia University .

Greenhouse GasesGreenhouse gases called CO2 , CH4, H2O, and other gases have heat trapping capacity and are needed to create green house effect that keeps the earth warm which is required

to support plants , animals, and humans. Relative contributions of radiatively – active gases to temperature rise-

Table-a

Concentration and increase of radiatively – active(greenhouse) gases Table-b

CO2 CH4 CFC O3 N2O H2O50% 19% 17% 8% 4% 2%

Greenhouse gas Concentration(ppm) Increase(%)/yearCO2 356(present) 0.4

CH4 1.7 1.0

N2O 0.3 0.3

CFC 0.0005 5

GREEN HOUSE GASES –OTHER SOURES Green house gases Natural sources Man-made sources

CH4 (Methane)

N2O(Oxides of nitrogen )

Water vapour

Carbons) CFCs(Chloroflouro carbons)

Bacterial decay of vegetable matter releases marsh gas which is mainly –methane.

Natural gas associated petroleum contains about 75% methane.

Coal pockets contain large amount of methane.

Anaerobic respiration – activities of micro-organisms in soil release nitrogen , nitrogen oxide & nitrous oxide.

Transpiration and evaporation in plants

Agricultural activities –Natural wetlands and rice paddies release

methane.Chemical processes gas drilling , coal

mining , biomass burning produce methane .

Agricultural activities –

Use of nirogenous fertilizers and soil cultivation release oxides of nitrogen .

Automobile exhausts Burning biomass

Chemicals used as –Coolants in A/Cs , cleaning solvents escape

as aerosols into the atmosphere .

More about greenhouse gases Carbon dioxide is commonly known as the green house gas.

Responsible for 50% greenhouse effect.CH4 is 20-30 times more effective than CO2 in trapping heat .

GLOBAL WARMING POTENTIAL (GWP)The potential of a greenhouse gas to cause greenhouse warmings expressed by

“global warming potential” Defined by – United nations intergovernmental panel on climatic change.

GWP sequencing for greehouse gas 10000X 150X 25X CFC < N2O < CH4 < CO2

In other words , CFC is 38 million times stronger , N2O 3800 times and methane 25 times stronger than CO2in terms of CO2 GWP.CO2 concentration increasing level -

Table - c Year Concentration (in ppm)

1880 283

Present (2010- 2016) 356

Radiation mediated GHE

Among the constituents of the atmosphere , only

carbon dioxide and water vapour strongly absorbed infrared radiation (14000-

25000nm) .Effectively block a large

fraction of the earth’s emitted radiation .The radiation thus

absorbed by CO2 and H2O vapour partly re- emitted to

the earth’s surface.The net result is that the earth’s surface gets heated up by a phenomenon called

the greenhouse effect.

GLOBAL WARMING SEASONAL CYCLE

REASONS OF GLOBAL WARMING

•Increase in CO2 concentration •Ozone depletion •Deforestation•Population increase

OZONE DEPLETION INTRODUCTION – OZONE gas –

Ozone is natural constituent of the atmosphere .it is bluish , explosive gas with a pronounced odour .

o OZONE LAYER

Ozone layer is the layer in the earth’s atmosphere which contains a relatively high concentration of ozone .

It absorbs 97-99% of the sun’s high frequency UV light which is damaging to life on earth.The ultra violet rays and infra red rays from the solar radiation , cannot reach the earth

directly and thus the ozone layer protects life on earth from harmful solar rays . LOCATION OF OZONE LAYER

Stratosphere Mainly located approximately 20-30 kms above the earth.

DISCOVERY OF OZONE LAYER French physicist – Charles Fabry in 1913

Unit of ozone concentration – Dobson (G. Dobson who developed Dobsometer )DISTRIBUTION OF OZONE LAYER

The thickness of the ozone layer varies geographically and seasonally.It is less thicker near the equator and larger towards the poles.

Thicker during spring in the northern hemisphere .Most of the ozone is created over the tropics , but the stratoscopic wind circulation transports

it polewards to northern and southern hemispheres .

Sources and sinks of CO2 There are uncertainties in the fluxes of CO2 . An overview of the fluxes per year is

given :•Emissions by use of fossil fuel , 20billiontonnes of CO2

•Emissions by deforestation and changes in land use , 5.5 billion tonnes of CO2

•Up take in the oceans, 5.5 billion tonnes CO2 •Uptake by CO2 fertilization , 7.3billion tonnes CO2

The major sink is the ocean which contains the bulk of dissolved carbon dioxide as bicarbonate.

Another important sink is the biomass , viz. living green plants, in which the photosynthesis rate is known to accelerate with increase in the CO2 level.

Impact of green house gases or global warming •Geographic •Climatic •Ecosystem •Agriculture & plant life Global climate = CO2 + H2O =vapour combine together to have a long – range impact on the global climate.It has been estimated that this combined effect will bring about 3 degree celcius rise in surface temperature , which may occur around 2050 A.D.It may be noted that at a slight increase in surface temperature, say 1 degree Celcius ,can adversely affect the world food production.

Prevention of global warming •Plant a tree

•Change a light •Drive less

•Recycle more•Use less hot water

•Turn off electronic devices after use •Spread the awareness •Adjust your thermostat

•Avoid products with lot of packeging

What Can be Done: AlternativesRenewable Energy Sources

Solar Energies Wind Power Biomass GeothermalChanges In Vehicle Systems

Hybrid Fuel Cell Battery-Electric

Up -to -date Information about global warming

According to IPCC (intergovernmental panel on climate change) , the temperature of the earth will

rise from 2 degree celcius to 6 degree celcius by the end of 21st century.

Scientists project rising sea levels will increase between 7and 22 inches by 2100.

About 50% of the country’s biodiversity would be at risk , 25% of the plant and animal species facing

extinction if the temperature rise exceeds 1.5 – 2.5 degree Celcius.

- ( IPCC 4th ASSESSMENT REPORT , BRUSSELS (6 APRIL , 2007)

9

Summary The increase in earth’s average surface temperature due to rising

levels of greenhouse gases .CH4 is 20-30 times more effective than CO2 in trapping heat .

In other words , CFC is 38 million times stronger , N2O 3800 times and methane 25 times stronger than CO2in terms of CO2

GWP(global warming potential ).Among the constituents of atmosphere , only carbon dioxide and

water vapour strongly absorbed infrared radiation (14000-25000nm) .

Ozone is natural constituent of the atmosphere .It is bluish , explosive gas with a pronounced odour .

It may be noted that at a slight increase in surface temperature, say 1 degree Celcius ,can adversely affect the world food

production.The major sink is the ocean which contains the bulk of dissolved

carbon dioxide as bicarbonate.Another important sink is the biomass , viz. living green plants, in

which the photosynthesis rate is known to accelerate with increase in the CO2 level.

References 1. DE A.K. , Environmental chemistry,

7th ed. , new age International publishers ,2010 (www.newagepublishers.com)2. Stanley E. Manahan , Environmental chemistry, 9th ed. , Taylor and Francis /CRC

press,2010 (www.crcpress.com)3. Singh, Kalpna; Sharma, Dr. Umesh; Pathak, S.K ; Realms of Environment & Ecology , 1st

ed. , Galgotia publications , 20124. Simplified ICSE Chemistry , STD. IX , DR. Viraf J. Dalal

5. http://web.mit.edu/12.000/www/m2010/finalwebsite/background/globalwarming/definition.html(1)6. https://www.environment.gov.au/climate-change/climate-science/greenhouse-effect(2)

7 . Data and image taken from official website of NASA (National Aeronautics and Space Administration )

THANK YOU